The Architecture Of An Integrated Fiber Optic LAN

Abstract

Digital transmission for voice and data signals are already employed in most fiber-optic communications. However, due to the requirement of high bit rate for each video signal and the extremely high added cost of digital encoding and decoding, it is still not practical to transmit digital video signals. In the forseeable future, video signals are very likely going to be transmitted in analog form through fiber links. This paper describes the architecture and the design of Short Bus Integrated Service Local Area Network (SBILAN), a local area network which provides voice, data, and video services. The network topology is a star dual short-bus with optical fiber distribution to all terminals. For economic reason, data and voice signals are transmitted in digital form through the parallel packet bus and video is transmitted in analog form through a circuit-switched bus. Digital and analog signals are multiplexed on the optic fiber transmission line by using frequency division multiplexing (FDM) technique. The parallel packet bus can transmit as fast as 160 Mbps and the bandwidth of the circuit switched bus is 4.5 MHz for one video channel. The fiber data link transmits the digital signals at a speed of 10 Mbps. An effective priority channel access scheme is employed that provides fast contention resolution and is collision-free on the packet bus. Details of the network design, the fiber data link design, and the integration methodology are provided.